Develop Reference

can the android emulator play audio

I wanted to record and pass through the recorded sound to the phone's speaker, but I could not get the recording code to work (app crashes, SEE MY ATTEMPT HERE) so I am now trying to see if the emulator can do anything related to audio or not. I copied a 1 sec recording, in both wav (16 bit pcm, 44k sampling frequency, mono) and mp3 (recording and conversion both done through Audacity) to the sdcard. I can see the files in the IDE's file explorer, so I guess the sdcard is being properly detected by the emulator. But I could not get the emulator's built in music player to detect them (Why ??).
As a second attempt, I copied the code HERE to the sample hello world Android app. Here's the main activity class
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// String PATH_TO_FILE = "/sdcard/asMP3.mp3";
// String PATH_TO_FILE = Environment.getExternalStorageDirectory().getPath()+"/asMP3.mp3";
String PATH_TO_FILE = Environment.getExternalStorageDirectory().getPath()+"/wavSigned16bitPCM.wav";
MediaPlayer mp1 = new MediaPlayer();
try
{
mp1.setDataSource(PATH_TO_FILE);
mp1.prepare();
mp1.start();
Toast.makeText(getApplicationContext(), "HERE", Toast.LENGTH_SHORT).show();
}
catch (IllegalArgumentException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IllegalStateException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (IOException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
I assumed this would start playing the sound as soon as the app starts. The Toast shows up so I know the code is executing. The program does not crash but nothing else happens either, no sound in this case as well (Why ?)
As a third attempt, I used the code HERE, and added the files I wanted to play in res\raw as it says. This program does not crash either, but I still cannot hear anything.
So the question is, is it possible to do anything at all related to audio, on the emulator? Looking at THIS QUESTION it looks like this should be possible, so why isn't it happening in my program? Do I need to set any permissions int he manifest for audio output as well?
----EDIT----
I have also seen THIS, but if I use the -useaudio option the emulator just says -useaudio is an unknown option, and emulator -help does not list it, hen it is clearly shown as an option in the developers website and moreover it says that useaudio is enabled by default. So why isn't my emulator playing any sound?
--- UPDATE ---
It seems the audio features do not work if the emulator has been started using a snapshot. If not, the audio feature still may or may not work depending on the computer. Please see HERE

Yes, you can do audio related work on emulator.
Your code sequence should be -
mp1 = new MediaPlayer();
mp1.setAudioStreamType(AudioManager.STREAM_MUSIC);
mp1.setDataSource(PATH_TO_FILE);
mp1.prepare();
mp1.start();
And for setting permissions in the manifest file.
Use these for record feature-
and these for playing feature -
There is a guide article on official android developer website
Guide to audio capture and
Guide to media playback
and if it dosn't work, then post your log cat screenshot.

Streaming to VideoView only plays on Wifi when using Samsung phones

I am using the following library to stream YouTube videos to an Android application.
http://code.google.com/p/android-youtube-player/source/browse/trunk/OpenYouTubeActivity/src/com/keyes/youtube/OpenYouTubePlayerActivity.java?r=3
I am successfully able to play videos on HTC and Motorola phones over 3G and Wifi. However, on Samsung Galaxy (Epic 4G) and Samsung Galaxy II phones I am only able to play using Wifi. 3G gives me this error: "Cannot play video. Sorry this video cannot be played."
I have tried forcing low quality YouTube streaming, but this did not help. I see in my log that Start() is being called in both cases (3G/Wifi). Is this an issue with VideoView? Is there a workaround?
Edit 2
The videos are coming from YouTube API. I have attempted using embedded and normal streams, as well as lowest quality stream available (varying per video). Also, I do not think it is an encoding issue since the same videos play correctly using Wifi.
Edit 1
I also receive the following output regardless of wether video plays using Wifi or does not using 3G.
01-30 15:22:38.305: E/MediaPlayer(3831): error (1, -1)
01-30 15:22:38.305: E/MediaPlayer(3831): callback application
01-30 15:22:38.305: E/MediaPlayer(3831): back from callback
01-30 15:22:38.309: E/MediaPlayer(3831): Error (1,-1)
According to this Link, these errors means the following (I think):
/*
Definition of first error event in range (not an actual error code).
*/
const PVMFStatus PVMFErrFirst = (-1);
/*
Return code for general failure
*/
const PVMFStatus PVMFFailure = (-1);
/*
/*
Return code for general success
*/
const PVMFStatus PVMFSuccess = 1;
/*
Further adding confusion.

Yes, as you are thinking, this is a issue in VideoView, similar issues also appear in MediaPlayer, and I've encountered similar and strange issues as you did, I had problems when the video was played only on 3G and not on Wi-Fi. This usually happens on 2.1 and some 2.2 devices, but not on higher API levels as I've seen so far.
So what I can recommend is do the following :
First check if the running device may be one that can have issues, something like this :
//Define a static list of known devices with issues
static List sIssueDevices=Arrays.asList(new String[]{"HTC Desire","LG-P500","etc"});
if(Build.VERSION.SDK_INT<9){
if(sIssueDevices.contains(Build.Device){
//This device may have issue in streaming, take appropriate actions
}
}
So this was the simplest part, to detect if the running device may have issues in streaming the video. Now, what I did and may also help you, is buffer the video from Youtube in a file on the SDCard and set that file as the source for your VideoView. I will write some code snippets to see how my approach was :
private class GetYoutubeFile extends Thread{
private String mUrl;
private String mFile;
public GetYotubeFile(String url,String file){
mUrl=url;
mFile=file;
}
#Override
public void run() {
super.run();
try {
File bufferingDir=new File(Environment.getExternalStorageDirectory()
+"/YoutubeBuff");
File bufferFile=new File(bufferingDir.getAbsolutePath(), mFile);
//bufferFile.createNewFile();
BufferedOutputStream bufferOS=new BufferedOutputStream(
new FileOutputStream(bufferFile));
URL url=new URL(mUrl);
URLConnection connection=url.openConnection();
connection.setRequestProperty("User-Agent", "Mozilla");
connection.connect();
InputStream is=connection.getInputStream();
BufferedInputStream bis=new BufferedInputStream(is,2048);
byte[] buffer = new byte[16384];
int numRead;
boolean started=false;
while ((numRead = bis.read(buffer)) != -1 && !mActivityStopped) {
//Log.i("Buffering","Read :"+numRead);
bufferOS.write(buffer, 0, numRead);
bufferOS.flush();
mBuffPosition += numRead;
if(mBuffPosition>120000 &&!started){
Log.e("Player","BufferHIT:StartPlay");
setSourceAndStartPlay(bufferFile);
started=true;
}
}
Log.i("Buffering","Read -1?"+numRead+" stop:"+mActivityStopped);
} catch (MalformedURLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void setSourceAndStartPlay(File bufferFile) {
try {
mPlayer.setVideoPath(bufferFile.getAbsolutePath());
mPlayer.prepare();
mPlayer.start();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
Another issue will arise when the VideoView has stopped playing before the end of file, because not enough was buffered in the file. For this you need to set an onCompletionListener() and if you are not at the end of the video, you should start again the video playback from the last position :
public void onCompletion(MediaPlayer mp) {
mPlayerPosition=mPlayer.getCurrentPosition();
try {
mPlayer.reset();
mPlayer.setVideoPath(
new File("mnt/sdcard/YoutubeBuff/"+mBufferFile).getAbsolutePath());
mPlayer.seekTo(mPlayerPosition);
mPlayer.start();
} catch (IllegalArgumentException e) {
e.printStackTrace();
} catch (IllegalStateException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
In the end, of course the GetYoutubeFile thread is started in the onCreate() method :
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
//init views,player,etc
new GetYoutubeFile().start();
}
Some modifications and adaptation I think will have to be done for this code, and it may not be the best approach, but it helped me, and I couldn't find any alternative.

I have tackle with this problem in my own way.First every time read your log cat.If you got
Error (1,-1)
that means you will get sorry,this video can not play message.So in this case finish that activity, give custom progress bar and download video.Then after downloading save it in temporary folder then play it.After playing delete that folder.
To reading log cat---
try {
Process process = Runtime.getRuntime().exec("logcat -d");
BufferedReader bufferedReader = new BufferedReader(
new InputStreamReader(process.getInputStream()));
StringBuilder log=new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) {
log.append(line);
}
} catch (IOException e) {
}
Read this answer too. although it is just user experience not linked to app.but it happens sometimes in default application also
Heaps of videos, even if I have full 3G network coverage, will say "Sorry, this video cannot be played". One day, I got so pissed off with it, I just kept pressing 'Okay' to dismiss the message, and then pressed the video again only to see the "Sorry, this video cannot be played" message again. I repeated this process (in my blind anger), but eventually, after about 5 tries, the video decided to miraculously play!
This method pretty much works for me every time. Most videos won't want to play the first time, but eventually if I am just persistent, and keep telling it to play even though it tells me it 'can't' play the video, it will play! Although, some videos i've had to press 'Okay', press the video, press 'Okay', press the video etc... for like 20 times before it actually decided to play. Those times, I have been incredibly close to getting my phone and throwing it down on the floor because of how shitty I am with how youtube won't work.
I wish there was a way to fix this problem. No one seems to have come up with a solution. Everyone just says "oh yeah I have the same problem" but no one contributes anything. GOOGLE, SOLVE THIS PROBLEM ON YOUR PHONES. THIS SEEMS TO BE HAPPENING WORLDWIDE, ON A RANGE OF ANDROID PHONES.

This message often cames from the inappropriate encoding of the video ("Cannot play video. Sorry this video cannot be played.") I was struggling with videoview for a while , now the correct encoded videos play on all tested devices, even when using Wifi or 3G. Let em know if you want to know how to encode the videos. And for streaming the videos I used the demo from android sdk apis and it works flawless.

VideoView / MediaPlayer Error (1, -18)

I have an application that is built to API level 2.2. This application contains a video that starts playing as soon as it is launched. The video is played inside a VideoView and the actually video file is stored in my internal storage (files directory for my apps package).
Most of the time it starts up just fine. But occasionally I get an error pop - up that says "Sorry, this video cannot be played." and has an Ok button. As soon as I press the ok button the video starts playing correctly. I need to figure out what is causing this error, or at the very least how I can catch whatever error it is and have it try again since it always works perfect after I hit ok. Inside the logs when this error box is shown I see these messages:
ERROR/PVOMXAudDecNode(21215): Ln 2232 OMX_EventError nData1 -2147479547 nData2 0
ERROR/PlayerDriver(21215): Command PLAYER_PREPARE completed with an error or info -18
ERROR/MediaPlayer(9282): message received msg=100, ext1=1, ext2=-18
ERROR/MediaPlayer(9282): error (1, -18)
ERROR/MediaPlayer(9282): callback application
ERROR/MediaPlayer(9282): back from callback
ERROR/MediaPlayer(9282): Error (1,-18)
DEBUG/VideoView(9282): Error: 1,-18
Where can I find a reference as to what exactly error code -18 indicates? And does anyone have any suggestions I could try to prevent it from happening in the first place. I have only observed This error on the Sprint Epic 4g.
Edit: well as far as I can tell no exceptions are getting thrown to me. I assume what is happening is that the video view knows to catch whatever exception is causing and it throws up the pop-up. Inside my log there is no exception stack trace just this reference to error -18.
As for how I am calling prepare. I use this:
mVideoView.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
#Override
public void onPrepared(MediaPlayer arg0) {
mVideoView.start();
}
});
and this:
mVideoView.setVideoPath(file.getAbsolutePath());
it calls prepare as part of setVideoPath (I assume it does anyway, but this method is undocumented). which causes onPrepared to get called in my listener.
Edit 2: for now i've just added an onErrorListener like so:
EDIT IMORTANT! this code will infinte error loop on ICS. For ICS devices I took out the setPath call, and returned false instead. It tries again by itself once and it succeeds.
mVideoView.setOnErrorListener(new OnErrorListener(){
#Override
public boolean onError(MediaPlayer arg0, int arg1, int arg2) {
Log.i(myTag, "MP ERROR: "+ arg1 + " - " + arg2);
mVideoView.setVideoPath(file.getAbsolutePath());
return true;
}
});
this catches the error and I can see in my logs that arg2 = -18 when this error happens. I just have it retry and return true so it doesn't throw up the dialog. So far i've never seen it fail twice in a row so this always starts the video correctly and doesn't make infinite loop.
I am still very interested if anyone can tell me exactly what error code -18 indicates though.

How do you catch potential exceptions thrown by prepare()? Do you catch IOException specifically and then retry calling the prepare()?
Try using prepareAsync() instead, which does not block and calls listener when player is ready. Also it does not throw IOException.

If you are running it on Froyo or Gingerbread the problem might be your device is not supporting playback of the file. Lower versions do not support videos encoded with formats other than baseline format. You may use some tools like video info on pc and check if the files are baseline formatted.

How to pause while the media scanner is running

I have an application that shows, plays and delete videos. I want to know that how to pause the current thread or processing while the media scanner is running. it takes about 4 to 7 seconds for media scanner to complete its activity..
any suggestions

If I understood you correctly you just need to implement the OnScanCompletedListener.
If not, add some code to clarify your question.

So if you want to know when the media scanner is done you have to register BroadcastReceiver which will listen for ACTION_MEDIA_SCANNER_FINISHED. Here is good presentation that gives good explanation of Intent, IntentFilter and BroadcastReceiver.

I use this code:)
while(!Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){
System.out.println("wait sdcard mount.");
try {
Thread.sleep(5000);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

Stagefright media delay in 2.2 after setting data source?

My first post here. This website has been very useful for learning Android programming, thanks to everyone.
I have a simple app that loads an MP3 stream and plays it. It works fine on 1.6 and 2.1 but on 2.2 it doesn't quite work right. It seems my service is having a problem starting, it's giving my an ANR and the dialog where I have to tap "Wait", and then finally the service starts. Why is the service taking a long time to start up?
Here's my simple code that sets the source and plays the audio:
public class MyActivityService extends Service {
MediaPlayer player = new MediaPlayer();
#Override
public IBinder onBind(Intent intent) {
return null;
}
#Override
public void onCreate() {
super.onCreate();
try {
player.setDataSource("URL OF MUSIC FILE");
} catch (IllegalArgumentException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IllegalStateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
try {
player.prepare();
player.setVolume(1, 1);
player.setLooping(true);
player.start();
Toast.makeText(getApplicationContext(), "Audio Service Started.", Toast.LENGTH_SHORT).show();}
ADDENDUM:
Turns out it wasn't my service not starting, it's the audio that's not starting quickly enough in 2.2...
I got rid of the ANRs when my service started and stopped by putting the onCreate() and onDestroy() methods of my service in their own threads, which is probably how it should have been from the beginning? Sorry, just learning.
But the delay that's the real problem remains, to clarify --
For example, my code, as it is right now, works fine and dandy and just how I want it to in 2.1 AND 2.2 when I set the data source to an MP3 file like this: http://dl.dropbox.com/u/6916184/TestSongStream.mp3
BUT when I set the data source to an audio stream location like this: http://d.liveatc.net/kjfk_twr or this: http://relay.radioreference.com:80/192236577 it works correctly ONLY in 2.1.
In 2.2 the sound does start playing eventually, but it takes "StagefrightPlayer" about 25 seconds or so after setting the data source until the audio starts as shown here:
07-31 02:54:30.176: INFO/StagefrightPlayer(34): setDataSource('http://relay.radioreference.com:80/192236577')
07-31 02:54:55.228: INFO/AwesomePlayer(34): calling prefetcher->prepare()
07-31 02:54:56.231: INFO/Prefetcher(34): [0x2cc28] cache below low water mark, filling cache.
07-31 02:54:56.337: INFO/AwesomePlayer(34): prefetcher is done preparing
07-31 02:54:56.347: DEBUG/AudioSink(34): bufferCount (4) is too small and increased to 12
07-31 02:54:57.337: ERROR/AwesomePlayer(34): Not sending buffering status because duration is unknown.
It also takes the same amount of time, about 25 seconds, to stop the media player after player.stop() is called in the onDestroy() method of my service, and the onDestroy() method continues on to Toast a message and cancel a notification.
Is that just the way it is with 2.2? If so, I can work around the delays, that's not a problem. Or more likely is it something I am doing wrong? But it works exactly as I want in 1.6 and 2.1!
Would posting more code help?
My code is very simple. There are no audio controls or anything like that. Simply a start audio button and stop audio button that start and stop a service that plays an audio stream.
Thank you for any help!

Do not call prepare() from the main application thread, particularly for a stream, because that may take much longer than you're allowed before an ANR. Use prepareAsync() instead. I have no idea if that is the root of your particular problem, but it would certainly be one cause of an ANR in your current implementation.